There are various types of electrical junctions boxes to be mounted on an automobile. One example of such electrical junction box includes a frame and a block to be attached to an inner side of the frame, as shown in FIGS. 7, 8 (refer to Patent Literature 1). FIG. 7 is a perspective view of a conventional electrical junction box in the middle of attaching the block to the frame. FIG. 8 is a perspective view of the frame shown in FIG. 7.
An electrical junction box 301 shown in FIG. 7 includes a frame 302, a block 103 arranged to be attached to an inner side of the frame 302, and various components such as a relay, fuse, bus bar or the like to be attached to the block 103.
The block 103 is made of synthetic resin and formed into a block-like shape, and is provided with a plurality of component attachment portions to which the various components mentioned above are attached. Also, a plurality of lock portions 104 is provided to a side face of the block 103. Each lock portion 104 includes a pair of rails 141 arranged parallel to each other and a projection 142 provided between the pair of rails 141.
The frame 302 is made of synthetic resin and formed into a frame-like shape. A plurality of lock receive portions 105 to which the lock portion 104 engages is provided to an inner face of the frame 302. As shown in FIG. 8, each lock receive portion 105 includes a pair of rails 151 arranged parallel to each other and a projection 152 provided between the pair of rails 151.
The lock portion 104 is engaged to the lock receive portion 105 by the pair of rails 141 being inserted between the pair of rails 151 of the lock receive portion 105 and the projection 142 being moved over the projection 152 of the lock receive portion 105 and caught to the projection 152. The block 103 is attached to the frame 302 by making the plurality of lock portions 104 engaged to the corresponding plurality of lock receive portion 105.